多主桁钢桁梁桥桥面荷载横向分配计算方法研究  

Study on calculation method of transverse distribution of deck load among muti-main-truss steel bridges

作　　者：韩衍群[1,2] 侯文崎[1] HAN Yanqun;HOU Wenqi(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Laboratory of High Speed Railway Construction,Central South University,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中南大学高速铁路建造技术国家工程实验室,湖南长沙410075

出　　处：《中南大学学报（自然科学版）》2023年第1期146-155,共10页Journal of Central South University:Science and Technology

基　　金：中国中铁股份有限公司科技研究开发计划项目(2020-重点-09);湖南省自然科学基金资助项目(2019JJ40385)。

摘　　要：针对多主桁钢桁梁桥桥面荷载在主桁间分配不均匀的现象,以三主桁钢桁梁桥为例提出桥面荷载横向分配简化计算模型,基于能量原理推导横向分配的简化计算公式,并对桥面荷载在主桁间横向分配的影响因素进行研究。研究结果表明:1)桥面荷载在主桁间横向分配主要受主桁、横联竖向刚度影响。在均布对称荷载作用下,荷载不均匀度系数α(即中桁受的总力与边桁之比)随主桁竖向刚度增加而增加,在支座处较大,约为3.33,靠近跨中逐渐减小,当主桁刚度在3.9×10^(4)kN/m以下时,α不大于1.17;2)横联竖向刚度是影响桥面荷载第二次分配的主要因素,α随横联刚度的增加而减小,横联竖向刚度在1.5×10^(5)~3.0×10^(5)kN/m范围内较合理;3)公式计算结果与空间有限元模型试验结果较吻合,验证了公式的正确性。研究成果可为类似桥梁简化计算提供依据。In multi-main-truss steel bridges,the load distribution of bridge deck among main trusses is uneven.Taking three-main-truss steel truss bridges as an example,a simplified calculation model for the transverse distribution of bridge deck load was proposed,and a simplified calculation formula for the transverse distribution was derived based on the energy principle,and the influencing factors of the transverse distribution of bridge deck load between the main trusses were studied.The results are shown as follows.1)The transverse distribution of deck load among main trusses is mainly affected by the vertical stiffness of main trusses and lateral bracings.Load nonuniformity factorα(the ratio of the total force on the middle truss to the side truss)increases with the increase of the vertical stiffness of the main truss.When the uniformly distributed symmetrical loadαis about 3.33 at the support,and gradually decreases near the midspan,and not more than 1.17 when the stiffness of the main truss is less than 3.9×10^(-4 )kN/m.2)Vertical stiffness of lateral bracings is the main factor affecting the second distribution of deck load.αdecreases with the increase of vertical stiffness of lateral bracings that is reasonable between 1.5×10^(-5) kN/m to 3.0×10^(-5) kN/m.3)The calculated results of the formula are in good agreement with those of spatial finite element model,which verifies the correctness of the formula.The research results can provide reference for the simplified calculation of similar bridges.

关 键 词：多主桁 横向分配 合理刚度 

分 类 号：U24[交通运输工程—道路与铁道工程]